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The Agami mechanism (1984) has an enamine intermediate with two proline units involved in the transition state (based on experimental reaction kinetics) [17] and according to a mechanism by Houk (2001) [18] [19] a single proline unit suffices with a cyclic transition state and with the proline carboxyl group involved in hydrogen bonding.
The Stork enamine alkylation involves the addition of an enamine to a Michael acceptor (e.g., an α,β -unsaturated carbonyl compound) or another electrophilic alkylation reagent to give an alkylated iminium product, which is hydrolyzed by dilute aqueous acid to give the alkylated ketone or aldehyde. [1] Since enamines are generally produced ...
Methyl ketone self-condensation is a side-reaction which can be avoided through the addition of TiCl 4 [12] into the reaction mixture (to act as a water scavenger). [13] [14] An example of an aldehyde reacting with a secondary amine to form an enamine via a carbinolamine intermediate is shown below: Enamine synthesis with a carbinolamine ...
The aldol reaction (aldol addition) is a reaction in organic chemistry that combines two carbonyl compounds (e.g. aldehydes or ketones) to form a new β-hydroxy carbonyl compound. Its simplest form might involve the nucleophilic addition of an enolized ketone to another: These products are known as aldols, from the ald ehyde + alcoh ol, a ...
The Leuckart reaction is the chemical reaction that converts aldehydes or ketones to amines by reductive amination in the presence of heat. [1][2] The reaction, named after Rudolf Leuckart, uses either ammonium formate or formamide as the nitrogen donor and reducing agent. [3] It requires high temperatures, usually between 120 and 130 °C; for ...
Proline organocatalysis. Proline organocatalysis is the use of proline as an organocatalyst in organic chemistry. This theme is often considered the starting point for the area of organocatalysis, even though early discoveries went unappreciated. [1] Modifications, such as MacMillan’s catalyst and Jorgensen's catalysts, proceed with excellent ...
The Hantzsch Pyrrole Synthesis, named for Arthur Rudolf Hantzsch, is the chemical reaction of β-ketoesters (1) with ammonia (or primary amines) and α-halo ketones (2) to give substituted pyrroles (3). [1][2] Pyrroles are found in a variety of natural products with biological activity, so the synthesis of substituted pyrroles has important ...
The reaction conditions are neutral or weakly acidic. [2] The intermediates of a reductive amination reaction. The amine first reacts with the carbonyl group to form a hemiaminal species which subsequently loses one molecule of water in a reversible manner by alkylimino-de-oxo-bisubstitution to form the imine intermediate. [3]